Check out example codes for "flutter status bar color". It will help you in understanding the concepts better.

Code Example 1

SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle(
  statusBarColor: Colors.white
));

Code Example 2

import 'package:flutter/services.dart';
 Widget build(BuildContext context) {
    SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle(
       statusBarColor: Color(0xFF2E7D32),
    ));
 
    return MaterialApp()

Code Example 3

return AnnotatedRegion<SystemUiOverlayStyle>(
  value: const SystemUiOverlayStyle(
    // For Android.
    // Use [light] for white status bar and [dark] for black status bar.
    statusBarIconBrightness: Brightness.light,
    // For iOS.
    // Use [dark] for white status bar and [light] for black status bar.
    statusBarBrightness: Brightness.dark,
  ),
  child: Scaffold(...),
);

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